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Bull Ants Feed at Twilight

Bull ants do not feed during all daylight hours. Observation has shown that they feed at twilight. When the sun is brighter for longer for example in summer, or there is no cloud cover, bull ants forage for food later in the day. When the sun is darker, earlier, they search for food sooner in the day. It was believed that all insects fed according to circadian rhythms, but this does not seem to be the case.

Activity in the nest was affected by cloud cover. Outside activity that involves feeding occurs at twilight. Obviously, they are feeding during these short intervals to avoid predators: most animals that eat ants would be inactive at twilight.

Tests were done at ANU in Canberra. Bull ants were put in containers where diffused light was altered. It was found they only fed when the light was set at a particular low level. Evolution does take some winding paths. This shows though that evolution develops in a rational way.

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Entomology

Vista Computer Solutions Blog

Society and High Intelligence Go Together

We have large brains due to social interaction. In early societies culture meant things had to be remembered. Another important function leading to large brains was tools use, though chimpanzees use tools. The most intelligent people would inevitably become leaders and have the choice of mates, thus passing on their genes.

Intelligence and brain size are of course interdependent. Animals such as dolphins and elephants have social structures. They are also very intelligent. Higher intelligence appears to be naturally selected for in any species.

Apparently, when society develops intelligence must increase otherwise an individual will be "put upon" by the smarter ones. There is some evidence that really clever individuals tend to be disruptive to a society. The naive are certainly at a disadvantage.

A thorn in the side of the above theory is that some highly structured societies are composed of small creatures with tiny brains. Ants, bees and wasps are in this category.

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Society

Ants Know Friend or Foe by Scent

If you are human, knowing one's enemies is easy. The brain evaluates another person as to whether he/she is friendly or not. It may be necessary to work alongside an enemy but the enemy tag still remains. Insects do not have have such advanced brain power to discriminate friend or foe.

Ants need a frame of reference to identify who they have to attack. When an ant from a colony meets an ant from another and they fight, the ants keep a memory of the enemies' odor. This occurs even though they may be of the same species. The "smell of fear" is passed on to fellow ants in the same colony. Ants also use scent to know other ants in their colony.

In tests individual ants were familiarized with individuals from another colony. They could see each other. Actual contact was prevented. When 20 intruders were placed near to the other colony they were attacked despite attackers knowing the other ants.

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Entomology

Giant Ants in Ancient North America

Big insects once roamed the US. They were very big. Ants were the size of small birds 50 million years ago. They are thought to have crossed the arctic land bridge that once existed between Europe and the US. The Green River site in Wyoming has given up many new finds in the past.

Bruce Archibald of Simon Fraser University in British Columbia noted that the fossil was similar to one found in Germany. Only the queen of the Dorylus wilverthi species of ant living today reaches this size. Fittingly, the new ant has been named Titanomyrma lubei. Louis Lube found the specimen. While this ant is big for North America, big ants probably lived in other parts of the world because large fossils of other creatures have been found there.

Large ants only live a tropical climate in the present so North America was tropical millions of years ago. It is a mystery how they crossed the temperate Arctic region then. For brief periods this area became quite warm, up to 8 degrees Celsius, though not tropical. Bursts of carbon dioxide into the atmosphere from sediment was the culprit. With two sources for ancient giant ants now known it may be possible to identify where they originated.

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Science

Bull Ants Feed at Twilight

Bull ants do not feed during all daylight hours. Observation has shown that they feed at twilight. When the sun is brighter for longer, for example in summer or there is no cloud cover, they forage for food later in the day. When the sun is darker, earlier, they search for food sooner in the day. It was believed that all insects fed according to circadian rhythms, but this does not seem to be the case.

Activity in the nest was affected by cloud cover. But outside activity that involves feeding occurs at twilight. Obviously, they are feeding during these short intervals to avoid predators. Most animals that eat ants would be inactive at twilight.

Tests were done at ANU in Canberra. Bull ants were put in containers where diffused light was altered. It was found they only fed when the light was set at a particularly low level. Evolution does take some winding paths. This shows though that evolution develops in a rational way.

. . . . . . . . . . . . . .